In conventional methods, the most widespread process for analyzing a periodic signal and extracting from it the principal characteristic variables is based primarily on detecting passages of this signal through zero.
Knowledge of the fundamental frequency of the periodic signal, acquired by chronometrical study of instants of passage to zero, then allows gradual deduction of the other principal characteristic variables of this signal.
Such an approach is nevertheless not very effective in the event of the frequency of the periodic signal in question reaching low values, the extension of the time interval between two successive passages to zero of this signal resulting in possibly unacceptable extension of the analysis time.
Mention may be made of for example U.S. Pat. No. 4,764,871, which proposes use of a Kalman filter to estimate the wheel speed. The Applicant has noted that said method is unfortunately rather greedy with regard to calculation time.